Yantraraja is a treatise on the construction of yantras, i. e. the armillary spheres, in five chapters, composed in S’ake 1292, by Mahendrasuri, pupil of Madanasuri and the chief astrologer of Firoz Shah Tughlak of Dehli ( 1351—1388A. D. ). The commentary is by the author’s pupil Malayendusuri. Published by S. Dvivedi and Lattara S’arma, Benaras, 1883